The present disclosure relates to a method for determining a leakage in a hydraulic brake system in a vehicle comprising a hydraulic footbrake and an automated hand brake, wherein the hand brake comprises an electromechanical actuator and acts on the same brake piston as the footbrake, wherein the method is characterized in that an actuation of the automated hand brake is taken into account in an evaluation of a suspected leakage. In addition, a device, a computer program, and a memory medium are provided.
So-called motor-on-caliper hand brakes are known from the prior art, such as, for example, from the patent application DE 10 2011 004 772 A1.
In addition, the patent application DE 10 2004 062 824 A1 is known from the prior art. This document relates to a method for checking the hand brake. The method is used for checking the proper performance of the pressure build-up in the hand brake. As a result, it is also possible to detect a circuit failure (a leakage in a brake line). For this purpose, the brake pressure is preferably brought to a high level (wherein the auxiliary piston is lifted) and an attempt is made to move the locking element which is preferably in the start position. Depending on whether the locking element can be moved or not, it is possible, in turn, to infer whether the pressure build-up is performing properly or whether there is a defect in the brake circuit. The cited document relates to a so-called APB-H, however, i.e., a parking brake which builds up the necessary holding pressure via application of hydraulic pressure. Monitoring systems that can detect leakages in the case of APB-H are therefore known from the prior art. Such methods cannot be applied to modern motor-on-caliper (MoC) APBs since the design does not contain the same components.
Since the piston moves and, therefore, volume is displaced during the build-up of clamping force in MoC hand brakes, however, monitoring systems such as, for example, leakage monitoring, can become active upon actuation of the MoC hand brake.